Re: [swift-users] Implicitly capture a mutating self

2016-12-16 Thread David Sweeris via swift-users 

> On Dec 16, 2016, at 15:54, Richard Wei via swift-users 
>  wrote:
> 
> Thanks. That’s true, but there are cases (like making BLAS calls) where I 
> have to nest more than 4 `withUnsafeMutable…` closures. It’s safe by really 
> clumsy. I just wish there were a cleaner way that looks like the do-notation 
> in Haskell or for-notation in Scala.

You might be able to do something with wrapper functions or operators. As long 
as you tell the compiler to always inline them, I don't think that'd cause any 
performance issues.

- Dave Sweeris
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Re: [swift-users] Implicitly capture a mutating self

2016-12-16 Thread Richard Wei via swift-users 
Thanks. That’s true, but there are cases (like making BLAS calls) where I have 
to nest more than 4 `withUnsafeMutable…` closures. It’s safe by really clumsy. 
I just wish there were a cleaner way that looks like the do-notation in Haskell 
or for-notation in Scala.

-Richard

> On Dec 16, 2016, at 14:16, Joe Groff  wrote:
> 
>> 
>> On Dec 16, 2016, at 12:10 PM, Richard Wei  wrote:
>> 
>> `sync` is not escaping. Shadow copy causes the device memory to make a copy, 
>> which can’t be a solution either. I’ll file a radar.
>> 
>>> Note that, independently, this part looks fishy:
>>> 
 try! fill<<<(blockSize, blockCount)>>>[
  .pointer(to: )
>>> 
>>> UnsafePointers formed by passing an argument inout are not valid after the 
>>> called function returns, so if this function is forming and returning a 
>>> pointer, it will likely result in undefined behavior. You should use 
>>> `withUnsafePointer() { p in ... }` to get a usable pointer.
>> 
>> This part is a semi-"type safe” wrapper to CUDA kernel launcher. The purpose 
>> is to make explicit which argument gets passed to the kernel as a pointer; 
>> in this case, self is a `DeviceArray`. `.pointer` is a factory method under 
>> `KernelArgument`. Since most arguments to the kernel are passed in by 
>> pointers, IMO using a bunch of `withUnsafe...` clauses would only make it 
>> look unnecessarily clumsy.
> 
> Unfortunately, that's the only defined way to write this code. The pointer 
> you get as an argument from `` is only good until pointer(to:) returns, 
> so it won't be guaranteed to be valid by the time you use it, and the 
> compiler will assume that `self` doesn't change afterward, so any mutation 
> done to `self` through that pointer will lead to undefined behavior. 
> Rewriting this code to use withUnsafePointer should also work around the 
> capture bug without requiring a shadow copy:
> 
>   let blockSize = min(512, count)
>   let blockCount = (count+blockSize-1)/blockSize
>   withUnsafePointer(to: ) { selfPtr in 
> device.sync { // Launch CUDA kernel
> try! fill<<<(blockSize, blockCount)>>>[
> .pointer(to: selfPtr), .value(value), .value(Int64(count))
> ]
> }
>  }
> 
> -Joe

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Re: [swift-users] Implicitly capture a mutating self

2016-12-16 Thread Joe Groff via swift-users 

> On Dec 16, 2016, at 12:10 PM, Richard Wei  wrote:
> 
> `sync` is not escaping. Shadow copy causes the device memory to make a copy, 
> which can’t be a solution either. I’ll file a radar.
> 
>> Note that, independently, this part looks fishy:
>> 
>>> try! fill<<<(blockSize, blockCount)>>>[
>>>   .pointer(to: )
>> 
>> UnsafePointers formed by passing an argument inout are not valid after the 
>> called function returns, so if this function is forming and returning a 
>> pointer, it will likely result in undefined behavior. You should use 
>> `withUnsafePointer() { p in ... }` to get a usable pointer.
> 
> This part is a semi-"type safe” wrapper to CUDA kernel launcher. The purpose 
> is to make explicit which argument gets passed to the kernel as a pointer; in 
> this case, self is a `DeviceArray`. `.pointer` is a factory method under 
> `KernelArgument`. Since most arguments to the kernel are passed in by 
> pointers, IMO using a bunch of `withUnsafe...` clauses would only make it 
> look unnecessarily clumsy.

Unfortunately, that's the only defined way to write this code. The pointer you 
get as an argument from `` is only good until pointer(to:) returns, so it 
won't be guaranteed to be valid by the time you use it, and the compiler will 
assume that `self` doesn't change afterward, so any mutation done to `self` 
through that pointer will lead to undefined behavior. Rewriting this code to 
use withUnsafePointer should also work around the capture bug without requiring 
a shadow copy:

   let blockSize = min(512, count)
   let blockCount = (count+blockSize-1)/blockSize
   withUnsafePointer(to: ) { selfPtr in 
 device.sync { // Launch CUDA kernel
 try! fill<<<(blockSize, blockCount)>>>[
 .pointer(to: selfPtr), .value(value), .value(Int64(count))
 ]
 }
  }

-Joe
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Re: [swift-users] Implicitly capture a mutating self

2016-12-16 Thread Joe Groff via swift-users 

> On Dec 15, 2016, at 11:46 PM, Richard Wei via swift-users 
>  wrote:
> 
> Hi,
> 
> Swift 3.0.2 seems to have broken my code due to mutating self capture. But I 
> have to pass inout self to the closure. Any workaround?
> 
> let blockSize = min(512, count)
> let blockCount = (count+blockSize-1)/blockSize
> device.sync { // Launch CUDA kernel
> try! fill<<<(blockSize, blockCount)>>>[
> .pointer(to: ), .value(value), .value(Int64(count))
> ]
> }

This looks like a compiler bug. Assuming `sync`'s closure is not @escaping, it 
should be allowed to capture self. If you haven't yet, would you be able to 
file a bug at bugs.swift.org? Does making a shadow copy work as a workaround, 
something like:

var tmpSelf = self
device.sync {...  ...}
self = tmpSelf

Note that, independently, this part looks fishy:

> try! fill<<<(blockSize, blockCount)>>>[
> .pointer(to: )

UnsafePointers formed by passing an argument inout are not valid after the 
called function returns, so if this function is forming and returning a 
pointer, it will likely result in undefined behavior. You should use 
`withUnsafePointer() { p in ... }` to get a usable pointer.

-Joe
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Re: [swift-users] Implicitly capture a mutating self

2016-12-16 Thread Zhao Xin via swift-users 
Below code should work:

let blockSize = min(512, count)
let blockCount = (count+blockSize-1)/blockSize

let boxedClosure = { (foo:inout MutableDeviceCollection) -> () in
device.sync { // Launch CUDA kernel
try! fill<<<(blockSize, blockCount)>>>[
.pointer(to: foo), .value(value), .value(Int64(count))
]
}
}

boxedClosure()

Zhaoxin

On Fri, Dec 16, 2016 at 5:12 PM, Richard Wei  wrote:

> The original file’s here:
> https://github.com/rxwei/cuda-swift/blob/master/Sources/
> Warp/CollectionOperations.swift
>
> I’m assuming this change has affected Dispatch users as well. It's not a
> good idea for such high-level APIs to rely on explicit pointers to pass
> mutating self for struct types.
>
> -Richard
>
> > On Dec 16, 2016, at 03:05, Richard Wei  wrote:
> >
> > It’s not the correct choice here :)
> >
> >> On Dec 16, 2016, at 03:04, Rien  wrote:
> >>
> >> Just because it is called “Unsafe” does not mean it is unsafe :-)
> >> It all depends on how you use it.
> >>
> >> Regards,
> >> Rien
> >>
> >> Site: http://balancingrock.nl
> >> Blog: http://swiftrien.blogspot.com
> >> Github: http://github.com/Swiftrien
> >> Project: http://swiftfire.nl
> >>
> >>
> >>
> >>
> >>> On 16 Dec 2016, at 09:52, Richard Wei  wrote:
> >>>
> >>> Zhao, it’s not a class.
> >>>
> >>> Rien, unsafe pointers is the last thing I would ever want to introduce
> in my library…
> >>>
> >>> Capturing self was clean, working perfectly, until Swift 3.0.2.
> >>>
> >>> -Richard
> >>>
>  On Dec 16, 2016, at 02:49, Zhao Xin  wrote:
> 
>  What is the type of self? If it is a class, try [unowned self].
> 
>  Zhaoxin
> 
> 
> 
> 
> 
> 
>  On Fri, Dec 16, 2016 at 4:33 PM, Rien via swift-users <
> swift-users@swift.org> wrote:
>  How about using:
> 
>  UnsafeMutablePointer
> 
>  ?
> 
>  Regards,
>  Rien
> 
>  Site: http://balancingrock.nl
>  Blog: http://swiftrien.blogspot.com
>  Github: http://github.com/Swiftrien
>  Project: http://swiftfire.nl
> 
> 
> 
> 
> > On 16 Dec 2016, at 09:10, Richard Wei via swift-users <
> swift-users@swift.org> wrote:
> >
> > Capturing makes it immutable, which unfortunately can't solve this
> problem.
> >
> > -Richard
> >
> >> On Dec 16, 2016, at 02:05, Zhao Xin  wrote:
> >>
> >> I did not test the code. But if you cannot implicitly capture a
> mutating self, you should do it explicitly, right?
> >>
> >> let blockSize = min(512, count)
> >> let blockCount = (count+blockSize-1)/blockSize
> >> device.sync { [self] () -> () in // Launch CUDA kernel
> >>   try! fill<<<(blockSize, blockCount)>>>[
> >>   .pointer(to: ), .value(value), .value(Int64(count))
> >>   ]
> >> }
> >>
> >> Hope above code works.
> >>
> >> Zhaoxin
> >>
> >> On Fri, Dec 16, 2016 at 3:46 PM, Richard Wei via swift-users <
> swift-users@swift.org> wrote:
> >> Hi,
> >>
> >> Swift 3.0.2 seems to have broken my code due to mutating self
> capture. But I have to pass inout self to the closure. Any workaround?
> >>
> >>   let blockSize = min(512, count)
> >>   let blockCount = (count+blockSize-1)/blockSize
> >>   device.sync { // Launch CUDA kernel
> >>   try! fill<<<(blockSize, blockCount)>>>[
> >>   .pointer(to: ), .value(value), .value(Int64(count))
> >>   ]
> >>   }
> >>
> >> 
> >>
> >> -Richard
> >>
> >> ___
> >> swift-users mailing list
> >> swift-users@swift.org
> >> https://lists.swift.org/mailman/listinfo/swift-users
> >>
> >>
> >
> > ___
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>  ___
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> 
> >>>
> >>
> >
>
>
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Re: [swift-users] Implicitly capture a mutating self

2016-12-16 Thread Richard Wei via swift-users 
It’s not the correct choice here :)

> On Dec 16, 2016, at 03:04, Rien  wrote:
> 
> Just because it is called “Unsafe” does not mean it is unsafe :-)
> It all depends on how you use it.
> 
> Regards,
> Rien
> 
> Site: http://balancingrock.nl
> Blog: http://swiftrien.blogspot.com
> Github: http://github.com/Swiftrien
> Project: http://swiftfire.nl
> 
> 
> 
> 
>> On 16 Dec 2016, at 09:52, Richard Wei  wrote:
>> 
>> Zhao, it’s not a class.
>> 
>> Rien, unsafe pointers is the last thing I would ever want to introduce in my 
>> library…
>> 
>> Capturing self was clean, working perfectly, until Swift 3.0.2.
>> 
>> -Richard
>> 
>>> On Dec 16, 2016, at 02:49, Zhao Xin  wrote:
>>> 
>>> What is the type of self? If it is a class, try [unowned self].
>>> 
>>> Zhaoxin
>>> 
>>> 
>>> 
>>> 
>>> 
>>> 
>>> On Fri, Dec 16, 2016 at 4:33 PM, Rien via swift-users 
>>>  wrote:
>>> How about using:
>>> 
>>> UnsafeMutablePointer
>>> 
>>> ?
>>> 
>>> Regards,
>>> Rien
>>> 
>>> Site: http://balancingrock.nl
>>> Blog: http://swiftrien.blogspot.com
>>> Github: http://github.com/Swiftrien
>>> Project: http://swiftfire.nl
>>> 
>>> 
>>> 
>>> 
 On 16 Dec 2016, at 09:10, Richard Wei via swift-users 
  wrote:
 
 Capturing makes it immutable, which unfortunately can't solve this problem.
 
 -Richard
 
> On Dec 16, 2016, at 02:05, Zhao Xin  wrote:
> 
> I did not test the code. But if you cannot implicitly capture a mutating 
> self, you should do it explicitly, right?
> 
> let blockSize = min(512, count)
> let blockCount = (count+blockSize-1)/blockSize
> device.sync { [self] () -> () in // Launch CUDA kernel
>try! fill<<<(blockSize, blockCount)>>>[
>.pointer(to: ), .value(value), .value(Int64(count))
>]
> }
> 
> Hope above code works.
> 
> Zhaoxin
> 
> On Fri, Dec 16, 2016 at 3:46 PM, Richard Wei via swift-users 
>  wrote:
> Hi,
> 
> Swift 3.0.2 seems to have broken my code due to mutating self capture. 
> But I have to pass inout self to the closure. Any workaround?
> 
>let blockSize = min(512, count)
>let blockCount = (count+blockSize-1)/blockSize
>device.sync { // Launch CUDA kernel
>try! fill<<<(blockSize, blockCount)>>>[
>.pointer(to: ), .value(value), .value(Int64(count))
>]
>}
> 
> 
> 
> -Richard
> 
> ___
> swift-users mailing list
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> https://lists.swift.org/mailman/listinfo/swift-users
> 
> 
 
 ___
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>>> 
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>> 
> 

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Re: [swift-users] Implicitly capture a mutating self

2016-12-16 Thread Rien via swift-users 
Just because it is called “Unsafe” does not mean it is unsafe :-)
It all depends on how you use it.

Regards,
Rien

Site: http://balancingrock.nl
Blog: http://swiftrien.blogspot.com
Github: http://github.com/Swiftrien
Project: http://swiftfire.nl




> On 16 Dec 2016, at 09:52, Richard Wei  wrote:
> 
> Zhao, it’s not a class.
> 
> Rien, unsafe pointers is the last thing I would ever want to introduce in my 
> library…
> 
> Capturing self was clean, working perfectly, until Swift 3.0.2.
> 
> -Richard
> 
>> On Dec 16, 2016, at 02:49, Zhao Xin  wrote:
>> 
>> What is the type of self? If it is a class, try [unowned self].
>> 
>> Zhaoxin
>> 
>> 
>> 
>> 
>> 
>> 
>> On Fri, Dec 16, 2016 at 4:33 PM, Rien via swift-users 
>>  wrote:
>> How about using:
>> 
>> UnsafeMutablePointer
>> 
>> ?
>> 
>> Regards,
>> Rien
>> 
>> Site: http://balancingrock.nl
>> Blog: http://swiftrien.blogspot.com
>> Github: http://github.com/Swiftrien
>> Project: http://swiftfire.nl
>> 
>> 
>> 
>> 
>> > On 16 Dec 2016, at 09:10, Richard Wei via swift-users 
>> >  wrote:
>> >
>> > Capturing makes it immutable, which unfortunately can't solve this problem.
>> >
>> > -Richard
>> >
>> >> On Dec 16, 2016, at 02:05, Zhao Xin  wrote:
>> >>
>> >> I did not test the code. But if you cannot implicitly capture a mutating 
>> >> self, you should do it explicitly, right?
>> >>
>> >> let blockSize = min(512, count)
>> >> let blockCount = (count+blockSize-1)/blockSize
>> >> device.sync { [self] () -> () in // Launch CUDA kernel
>> >> try! fill<<<(blockSize, blockCount)>>>[
>> >> .pointer(to: ), .value(value), .value(Int64(count))
>> >> ]
>> >> }
>> >>
>> >> Hope above code works.
>> >>
>> >> Zhaoxin
>> >>
>> >> On Fri, Dec 16, 2016 at 3:46 PM, Richard Wei via swift-users 
>> >>  wrote:
>> >> Hi,
>> >>
>> >> Swift 3.0.2 seems to have broken my code due to mutating self capture. 
>> >> But I have to pass inout self to the closure. Any workaround?
>> >>
>> >> let blockSize = min(512, count)
>> >> let blockCount = (count+blockSize-1)/blockSize
>> >> device.sync { // Launch CUDA kernel
>> >> try! fill<<<(blockSize, blockCount)>>>[
>> >> .pointer(to: ), .value(value), .value(Int64(count))
>> >> ]
>> >> }
>> >>
>> >> 
>> >>
>> >> -Richard
>> >>
>> >> ___
>> >> swift-users mailing list
>> >> swift-users@swift.org
>> >> https://lists.swift.org/mailman/listinfo/swift-users
>> >>
>> >>
>> >
>> > ___
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>> > swift-users@swift.org
>> > https://lists.swift.org/mailman/listinfo/swift-users
>> 
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Re: [swift-users] Implicitly capture a mutating self

2016-12-16 Thread Zhao Xin via swift-users 
What is the type of self? If it is a class, try [unowned self].

Zhaoxin






On Fri, Dec 16, 2016 at 4:33 PM, Rien via swift-users  wrote:

> How about using:
>
> UnsafeMutablePointer
>
> ?
>
> Regards,
> Rien
>
> Site: http://balancingrock.nl
> Blog: http://swiftrien.blogspot.com
> Github: http://github.com/Swiftrien
> Project: http://swiftfire.nl
>
>
>
>
> > On 16 Dec 2016, at 09:10, Richard Wei via swift-users <
> swift-users@swift.org> wrote:
> >
> > Capturing makes it immutable, which unfortunately can't solve this
> problem.
> >
> > -Richard
> >
> >> On Dec 16, 2016, at 02:05, Zhao Xin  wrote:
> >>
> >> I did not test the code. But if you cannot implicitly capture a
> mutating self, you should do it explicitly, right?
> >>
> >> let blockSize = min(512, count)
> >> let blockCount = (count+blockSize-1)/blockSize
> >> device.sync { [self] () -> () in // Launch CUDA kernel
> >> try! fill<<<(blockSize, blockCount)>>>[
> >> .pointer(to: ), .value(value), .value(Int64(count))
> >> ]
> >> }
> >>
> >> Hope above code works.
> >>
> >> Zhaoxin
> >>
> >> On Fri, Dec 16, 2016 at 3:46 PM, Richard Wei via swift-users <
> swift-users@swift.org> wrote:
> >> Hi,
> >>
> >> Swift 3.0.2 seems to have broken my code due to mutating self capture.
> But I have to pass inout self to the closure. Any workaround?
> >>
> >> let blockSize = min(512, count)
> >> let blockCount = (count+blockSize-1)/blockSize
> >> device.sync { // Launch CUDA kernel
> >> try! fill<<<(blockSize, blockCount)>>>[
> >> .pointer(to: ), .value(value), .value(Int64(count))
> >> ]
> >> }
> >>
> >> 
> >>
> >> -Richard
> >>
> >> ___
> >> swift-users mailing list
> >> swift-users@swift.org
> >> https://lists.swift.org/mailman/listinfo/swift-users
> >>
> >>
> >
> > ___
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>
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Re: [swift-users] Implicitly capture a mutating self

2016-12-16 Thread Rien via swift-users 
How about using:

UnsafeMutablePointer

?

Regards,
Rien

Site: http://balancingrock.nl
Blog: http://swiftrien.blogspot.com
Github: http://github.com/Swiftrien
Project: http://swiftfire.nl




> On 16 Dec 2016, at 09:10, Richard Wei via swift-users  
> wrote:
> 
> Capturing makes it immutable, which unfortunately can't solve this problem.
> 
> -Richard
> 
>> On Dec 16, 2016, at 02:05, Zhao Xin  wrote:
>> 
>> I did not test the code. But if you cannot implicitly capture a mutating 
>> self, you should do it explicitly, right?
>> 
>> let blockSize = min(512, count)
>> let blockCount = (count+blockSize-1)/blockSize
>> device.sync { [self] () -> () in // Launch CUDA kernel
>> try! fill<<<(blockSize, blockCount)>>>[
>> .pointer(to: ), .value(value), .value(Int64(count))
>> ]
>> }
>> 
>> Hope above code works.
>> 
>> Zhaoxin
>> 
>> On Fri, Dec 16, 2016 at 3:46 PM, Richard Wei via swift-users 
>>  wrote:
>> Hi,
>> 
>> Swift 3.0.2 seems to have broken my code due to mutating self capture. But I 
>> have to pass inout self to the closure. Any workaround?
>> 
>> let blockSize = min(512, count)
>> let blockCount = (count+blockSize-1)/blockSize
>> device.sync { // Launch CUDA kernel
>> try! fill<<<(blockSize, blockCount)>>>[
>> .pointer(to: ), .value(value), .value(Int64(count))
>> ]
>> }
>> 
>> 
>> 
>> -Richard
>> 
>> ___
>> swift-users mailing list
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>> https://lists.swift.org/mailman/listinfo/swift-users
>> 
>> 
> 
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Re: [swift-users] Implicitly capture a mutating self

2016-12-16 Thread Zhao Xin via swift-users 
I did not test the code. But if you cannot implicitly capture a mutating
self, you should do it explicitly, right?

let blockSize = min(512, count)
let blockCount = (count+blockSize-1)/blockSize
device.sync { *[self] () -> () in* // Launch CUDA kernel
try! fill<<<(blockSize, blockCount)>>>[
.pointer(to: ), .value(value), .value(Int64(count))
]
}

Hope above code works.

Zhaoxin

On Fri, Dec 16, 2016 at 3:46 PM, Richard Wei via swift-users <
swift-users@swift.org> wrote:

> Hi,
>
> Swift 3.0.2 seems to have broken my code due to mutating self capture. But
> I have to pass inout self to the closure. Any workaround?
>
> let blockSize = min(512, count)
> let blockCount = (count+blockSize-1)/blockSize
> device.sync { // Launch CUDA kernel
> try! fill<<<(blockSize, blockCount)>>>[
> .pointer(to: ), .value(value), .value(Int64(count))
> ]
> }
>
>
> -Richard
>
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[swift-users] Implicitly capture a mutating self

2016-12-15 Thread Richard Wei via swift-users 
Hi,

Swift 3.0.2 seems to have broken my code due to mutating self capture. But I 
have to pass inout self to the closure. Any workaround?

let blockSize = min(512, count)
let blockCount = (count+blockSize-1)/blockSize
device.sync { // Launch CUDA kernel
try! fill<<<(blockSize, blockCount)>>>[
.pointer(to: ), .value(value), .value(Int64(count))
]
}



-Richard___
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